Current mobile terminals can have several different radio parts. For example one for connecting the mobile terminal to a cellular network, one for connecting the terminal to a wireless LAN network and one for connecting the terminal to a Bluetooth device. In addition it can have a FM-radio part for the listening of the broadcast stations.
It usually is easy to integrate the antennas of the different radio parts inside the mobile terminal because of the small wavelengths used in for example GSM, WLAN and Bluetooth. On the other hand, it can be difficult to integrate a FM-radio antenna inside a small mobile terminal because of the larger antenna sizes resulting from the larger wavelengths used.
Traditionally the FM-radio antenna of the mobile terminal has used the cord of the portable hands-free unit or the earplugs. Because of this the FM-radio of the mobile terminal can not be used without attaching the hands-free unit even if the mobile terminal has a suitable speaker for radio listening.
A solution to the above mentioned problem could be the usage of an external wire antenna attached to the connector of the portable hands-free unit or the usage of an external whip antenna. These solutions however are external units, and do not bring any solution to the integration of FM-radio antenna to the mobile terminal, especially inside the terminal.
From the publication U.S. 2003/0234743 is know an approach to solve the above mentioned problem. In the publication is described an antenna element incorporated in the hinge mechanism of a mobile terminal. The antenna of the publication is preferably a dual band antenna that is intended to be used on for example DCS or GSM frequencies (1800 MHz and 900 MHz frequency ranges).
At these frequencies the antenna can be very small, at least if on the lower frequency range (900 MHz) a helical antenna element is used. This helical antenna element also acts as the spring of the hinge mechanism, that is it is a functional part of the mobile terminal. This exposes the antenna element to mechanical stress and it can break down.